Liquid fuel pumping apparatus



March 3, 1970 n. F. MOWBRAY LIQUID FUEL PUMPING APPARATUS 2 Sheets-Sheet1 Filed Oct 31 -1968 wy ma a ATTORNEYS March 3, 1970 D. F. MOWBRAY3,498,226

LIQUID FUEL PUMPING APPARATUS Filed 001:. 31,- 1968 2 Sheets-Sheet 2 7/|o H\ {E7 Z6- 26 8A 27 22-h g ATORNEYS atent Ofitice 3,498,226 PatentedMar. 3, 1970 3,498,226 LIQUID FUEL PUMPING APPARATUS Dorian FarrarMowbray, Burnham, England, assignor to C.A.V. Limited, London, England,a British company Filed Oct. 31, 1968, Ser. No. 772,163 Claims priority,application Great Britain, Nov. 6, 1967, 50,291/ 67 Int. Cl. F0411 1/00,1/04;F02m 39/00 US. Cl. 103-2 1 Claim ABSTRACT F THE DISCLOSURE Thisinvention relates to liquid fuel pumping apparatus for supplying liquidfuel to a six-cylinder compression ignition internal combustion enginehaving unequal firing angles, and the object of the invention is toprovide such apparatus in a simple and convenient form.

Apparatus in accordance with the invention comprises in combination, abody part, a rotary distributor mounted within the body part and adaptedto be driven in timed relationship with the engine with which theapparatus is associated, six outlet ports formed in the body part andthrough which fuel flows in turn to the combustion spaces of the enginerespectively, the outlet ports opening onto the periphery of thedistributor member at angularly spaced points, the spacing of whichcorresponds to the required firing angle, a delivery passage formed inthe distributor member for registration with the outlet ports in turn,three equiangularly spaced radial bores formed in the distributormember, the inner ends of said bores communicating with said deliverypassage, three pumping plungers located within said bores respectively,a cam surrounding the distributor member, two sets of cam lobes formedon the internal periphery of the cam each set comprising threeequiangularly spaced cam lobes and the lobes of each set being spaced bythe required firing angle, the cam lobes acting to impart movement tothe plungers during the time when the delivery passage is in registerwith an outlet port, three inlet passages formed in the distributormember and opening out onto the pheriphery thereof at equiangularlyspaced points, said inlet passages communicating with the inner ends ofsaid bores, a pair of ports formed in the body part for registrationwith said inlet passages, said bores being angularly spaced by an amountso as to be placed in communication with the bores by way of said inletpassages alternately and during the time when the plungers are permittedto move outwardly by the cam lobes, a pair of cylinders formed in thebody part in communication at one end with said ports respectively, apair of reciprocable shuttles respectively mounted in said cylinders,means for feeding fuel to said ends of the cylinders in turn whilst theyare out of communication with said inlet passages, throttle means forcontrolling the quantity of fuel fed to said ends of the cylinders,thereby to control the extent of movement of the shuttles therein, andmeans for feeding fuel to the opposite ends of said cylinders to movethe shuttles therein towards said ends thereof during the time when aninlet passage is in communication with one of the ports.

In the accompanying drawings:

FIGURE 1 is a sectional side elevation on the line 11 of FIGURE 3 of oneexample of liquid fuel pumping apparatus in accordance with theinvention,

FIGURE 2 is a section on the line 22 of FIGURE 1 and FIGURE 3 is asection on the line 33 of FIGURE 1.

The drawings show a liquid fuel pumping apparatus capable of supplyingfuel to a six-cylinder compression ignition engine of the V-type. Theangle between the two banks of cylinders of the engine is and theparticular engine requires fuel to be supplied to it at unequalintervals of pump rotation of 45, 75, 45, 75 etc. It will be appreciatedhowever that the apparatus is equally able to supply fuel to engineshaving 60 or V angles, and to a conventional six cylinder engine havingits cylinders in line provided various angles within the apparatus arealtered accordingly.

The apparatus comprises a body part 10 in which is mounted a rotarycylindrical distributor 11 which is adapted to be driven in timedrelationship with the engine with which the apparatus is associated. Atone end of the disributor is formed three radially extendingequi-angularly spaced bores 20 which accommodate pumping plungers 19respectively. Bearing against the outer ends of the pumping plungers areshoe pieces respectively, each of which mounts a roller 21 whichcooperates to effect inward movement of the associated pumping plunger,with cam lobes formed on the internal periphery of an annular cam ring18 which surrounds the distributor at this point. The cam ring is formedwith two sets 53, 54 of lobes and each set comprises three lobes whichare equi-angularly spaced relative to each other about the axis ofrotation of the distributor. Moreover, the two sets of cam lobes areangularly spaced from each other by 45. The effect of this spacing isthat all three pumping plungers 50 are moved inwardly simultaneously todeliver fuel at 45, 75 45, etc intervals of pump rotation.

The inner ends of the bores 20 which accommodate the pumping plungersare in communication with each other, and also with a longitudinalpassage 22 formed in the distributor. At one point, the longitudinalpassage is in communication with a radially disposed delivery passage23, and this is arranged to register in turn, as the distributorrotates, with six outlet ports 24 which are formed in the body part. Thecircumferential spacing of the outlet ports 24 corresponds with thespacing of the sets of cam lobes and the delivery passage 23 is arrangedto register with an outlet port during the time when the pumpingplungers are being moved inwardly by the cam lobes. In use, the outletports are connected to the fuel injection nozzles 25 of the associatedengine.

The longitudinal passage 22 is also in communication with three inletpassages 26 which extend to points on the periphery of the distributormember, the points being equiangularly spaced relative to each other.Moreover, formed in the body part are a pair of inlet ports 30, 31 forcommunication with the inlet passages 26, the ports being spaced by anangle of 45. The ports are in communication respectively with the innerends of a pair of cylinders 32, 33 defined in the body part and whichcontains reciprocable shuttles 34, 35, respectively. The inlet passages26 and the inlet ports 30, 31 are positioned that an inlet passage isbrought into register with one inlet port during the time when theplungers are permitted to move outwardly by the cam lobes and duringthis time fuel flows through this inlet port in a manner which will bedescribed, to the bores 20 containing the pumping plungers 19 thereby tomove the latter in an outward direction. This part of the cycle ofoperation of the apparatus is described as a filling stroke, and thenext filling stroke occurs after an injection stroke, and during thetime when the aforesaid inlet passages move into register with the otherinlet port.

Also mounted within the body part is a feed pump 13 of the vane type,the rotary parts of the feed pump being secured to the end of thedistributor remote from the bores. The feed pump is provided with aninlet 14 for connection to a source of fuel, and an outlet 15, and theinlet and outlet are in communication with each other by Way of a reliefvalve 16 which controls the outlet pressure of the feed pump.

Also formed on the periphery of the distributor member are three grooves27 which are equiangularly spaced relative to each other and which arepositioned at 60 intervals relative to the inlet passages 26. Thegrooves 27 are in communication with a circumferential groove which isformed in the periphery of the distributor and which is in communicationwith the outlet 15 of the feed pump by way of the throttle valve 28which can be adjusted to determine the rate at which the fuel flows fromthe outlet of the feed pump through passage 29 to the circumferentialgroove. The aforesaid grooves 27 register with the inlet ports 30, 31 inturn, during the time when the inlet passages 26 are out of registertherewith. Considering the inlet port 30 and the associated shuttle 34,during delivery of fuel to the bores 20, the shuttle 34 is moved towardsthe inner end of the cylinder 32. After the inlet passage 26 has movedout of register with the inlet port, one of the aforesaid grooves 27 isbrought into register therewith, and fuel flows to the inner end of thecylinder 32 thereby moving the shuttle outwardly. The quantity of fuelwhich flows to the inner end of the cylinder is determined by thesetting of the throttle valve 28, and it is this quantity of fuel whichis subsequently passed to the aforesaid bores for injection to theassociated engine.

During the outward movement of the shuttle 34, fuel is displaced fromthe outer end of its cylinder and for this purpose there is provided incommunication with the outer end of the cylinder a drain passage 45. Thedrain passage 45 opens onto the periphery of the distributor member at apoint axially removed from but angularly aligned with the port 30. Thisis illustrated in FIGURE 1 and a similar passage is provided for thecylinder 33 which contains the other shuttle. For registration with thedrain passages at the appropriate time there are provided in theperiphery of the distributor member three drain grooves 44. These areangularly aligned with the grooves 27 respectively and communicate witha circumferential groove formed in the periphery of the distributormember which is in constant communication with a drainage space definedin the body part of the apparatus. Thus, when fuel flows through agroove 27 to the inner ends of the cylinders to move the shuttlesoutwardly, fuel flows from the outer ends of the cylinders by way of theappropriate drain passage and a drain groove 44.

In order to effect inward movement of the shuttles 34, 35 during afilling stroke fuel under pressure from the outlet 15 of the feed pumpis supplied to the outer ends of the cylinders containing the shuttle.For this pur pose the outer ends of the cylinders are in communicationrespectively with a pair of supply passages which open out onto theperiphery of the distributor member at a point axially removed from butangularly aligned with the respective inlet ports. As shown in FIGURE 2the supply passage associated wi.h the cylinder containing the shuttle34 is referenced 43. For registration with the supply passages there areprovided in the periphery of the distributor member three equiangularlyspaced supply grooves 42 which are angularly aligned with the inletpassages 26, and which communicate with a circumferential groove whichis in constant communication with the outlet 15 of the feed pump by wayof the passage 29. Thus during a filling stroke when a passage 26 is incommunication with an inlet port fuel is supplied to the outer end ofthe associated cylinder to move the shuttle inwardly.

At the outer ends of the cylinders 32, 33 are mounted a pair of stops36, 37, respectively, the setting of which can be varied by means of afluid pressure operable piston 38. This piston is loaded by means of acoiled compression spring 39 in one direction, and is moved inopposition to the spring by fuel under pressure derived directly fromthe outlet of the feed pump through passage 29. The piston has mountedtherein a pair of members 40 which have cam surfaces defined on theirsides which are presented to the stops. Moreover, the members areadjustably mounted within the piston, and can be adjusted by means of apair of adjustors 41 respectively operable from the exterior of theapparatus. In the particular example, the cam surfaces are shaped sothat as the output pressure of the feed pump increases, the permittedextent of movement of the shuttles within their cylinders is reduced.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. A liquid fuel pumping apparatus for supplying fuel to a six-cylindercompression ignition internal combustion engine having unequal firingangles the apparatus comprising in combination, a body part, a rotarydistributor mounted within the body part and adapted to be driven intimed relationship wi.h the engine with which the apparatus isassociated, six outlet ports formed in the body part and through whichfuel flows in turn to the combustion spaces of the engine respectively,the outlet ports opening onto the periphery of the distributor member atangularly spaced points, the spacing of which corresponds to therequired firing angle, a delivery passage formed in the distributormember for registration with the outlet ports in turn, threeequiangularly spaced radial bores formed in the distributor member, theinner ends of said bores communicating with said delivery passage. threepumping plungers located within said bores respectively, a camsurrounding the distributor member, two sets of cam lobes formed on theinternal periphery of the cam, each set comprising three equiangularlyspaced cam lobes and the lobes of each set being spaced by the requiredfiring angle, the cam lobes acting to impart inward movement to theplungers during the time when the delivery passage is in register withan outlet port, three inlet passages formed in the distributor memberand opening out onto the periphery thereof at equiangularly spacedpoints, said inlet passages communicating with the inner ends of saidbores, a pair of ports formed in the body part for registration withsaid inlet passages, said bores being angularly spaced by an amount soas to be placed in communication with the bores by way of said inletpassages alternately and during the time when the plungers are permittedto move outwardly by the cam lobes, a pair of cylinders formed in thebody part in communication at one end with said ports respectively, apair of reciprocable shuttles respectively mounted in said cylinders,means for feeding fuel to said ends of the cylinders in turn whilst theyare out of communication with said inlet passages, throttle means forcontrolling the quantity of fuel fed to said ends of the cylinders.thereby to control the extent of movement of the shuttles therein, andmeans for feeding fuel to the opposite ends or 5 n 6 said cylinders tomove the shuttles therein towards said 3,267,861 8/1966 Pigeronlet eta1. ends thereof during the time when an inlet passage is in 3,319,6165/ 1967 Glikin 123-139 communication with one of the ports.

DONLEY J. STOCKING, Primary Examiner References Cited 5 W. I. KRAUSS,Assistant Examiner UNITED STATES PATENTS U S 1 XR 2,819,677 1953 l th 1X 103-174; 1 I l 2,901,974 9/1959 Evans 103-161X

